1. Field of the Invention
The present invention relates to an engine for a vehicle, particularly to an engine for a vehicle provided with a breather chamber.
2. Description of the Related Art
A breather chamber of an engine for a vehicle has a function of separating the air (blow-by gas) including oil mist in a crankcase into gas and liquid, returning an oil component to the interior of the engine, and discharging a gas component to the exterior of the crankcase.
Japanese Patent Application No. 2008-332653 discloses an engine for a vehicle having a breather chamber. The breather chamber is provided on the upper side of a crankcase. The crankcase is dividable into left and right crankcase members at vertical mating surfaces (division surfaces), and the breather chamber is formed by the mating surfaces of both the crankcase members.
In an engine for a vehicle provided with a crankcase dividable into upper and lower crankcase members at horizontal mating surfaces (division surfaces), a breather chamber is added onto an upper surface of the upper crankcase member, or a breather chamber is formed by the mating surfaces of the upper and lower crankcase members.
3. Problems to be Solved by the Invention
As in the former engine for the vehicle described above, when the breather chamber is formed by the mating surfaces of the left and right crankcase members, the breather chamber is arranged in a center part of width of a transmission chamber housing a gear type transmission in the crankshaft direction, so that the capacity of the breather chamber is limited.
Meanwhile, as in the latter engine for the vehicle described above, when the breather chamber is added onto an upper part of the crankcase, a starter and the like to be arranged onto the upper part of the crankcase are arranged at higher positions, and thus the total length of the engine is increased. Particularly, since a rear cylinder inclined rearward is positioned on the upper side of the crankcase in a V-type engine, the capacity of the breather chamber is largely limited.
When the breather chamber is provided in the exterior of the crankcase, a case and a cover exclusive to the breather chamber are required and a pipe for retuning oil is also required. Thus, part cost is increased and the man-hours required for assembling the engine are also increased.